Global wildlife populations down by half since 1970: WWF
GENEVA (Reuters) – The world populations of fish, birds, mammals, amphibians and reptiles fell overall by 52 percent between 1970 and 2010, far faster than previously thought, the World Wildlife Fund said
http://www.reuters.com/article/2014/09/29/us-environment-wildlife-idUSKCN0HO2A120140929